Field of the Invention
The present invention relates to an image forming apparatus, a method for controlling the same, a recording medium, and an image forming system.
Description of the Related Art
In recent years, a shutdown function for flexibly turning off the power state of an image forming apparatus has been proposed as the demand for a power saving of appliances has increased. As examples of the shutdown function, there are an auto shutdown function, a weekly shutdown function, and a remote shutdown function.
The auto shutdown function is to start a timer when an image forming apparatus is brought into a sleep state and maintain the sleep state. The timer is stopped when a predetermined period of time elapses to automatically turn off the image forming apparatus.
The weekly shutdown function is to previously set a day of the week and the image forming apparatus is automatically turned off when the time counted by a timer of the image forming apparatus reaches the set time.
Further, by the remote shutdown function, the image forming apparatus is remotely turned off by an external apparatus using a Management Information Base (MIB) of a Simple Mail Transfer Protocol (SMPT) or a unique application programming interface (API).
The image forming apparatus is turned off by the above shutdown function to enable power saving of the image forming apparatus. On the other hand, there is a demand for the power saving of the image forming apparatus even in the case where the image forming apparatus is not in an off-state. A technique to save the power of the image forming apparatus has been known, by which power is supplied to a device only when the device is used, in the case where the image forming apparatus is not in the off-state (refer to Japanese Patent Application Laid-Open Nos. 5-162421 and 8-238822). In the image forming apparatus discussed in Japanese Patent Application Laid-Open Nos. 5-162421 and 8-238822, a printer is energized (powered) only when a print function is used and the printer is not energized (powered) when the print function is not used.
The image forming apparatus can be connected to a post-processing apparatus for discharging, sorting, stapling, punching, and cutting a paper output from the image forming apparatus. In general, the image forming apparatus and the post-processing apparatus use their respective power supplies different from each other. More specifically, a switch for shutting down a controller unit mounted on the image forming apparatus (hereinafter referred to as a main body controller), a scanner unit, a printer unit, a FAX unit, various boards and chips, and the image forming apparatus use a power supply different from a switch for shutting down a controller unit mounted on a finisher apparatus (hereinafter referred to as a finisher controller) and shutting down the finisher controller. Therefore, both switches for the image forming apparatus and the finisher apparatus need to be turned off to shut down both the image forming apparatus and the finisher apparatus by the above shutdown function. In a printing system equipped with the image forming apparatus and the finisher apparatus connected to the image forming apparatus, the finisher apparatus is communicably connected to a printer unit to handle the paper printed by the printer unit of the image forming apparatus. For this reason, the image forming apparatus communicates with the finisher apparatus via the printer unit. For this reason, if the shutdown function is to be executed, the main body controller of the image forming apparatus notifies the finisher controller of an operation end via the printer unit.
However, as discussed in Japanese Patent Application Laid-Open Nos. 5-162421 and 8-238822, the printer unit through which an end notification between the main body controller and the finisher controller goes is not always constantly supplied with power. If the supply of power to the printer unit is stopped, the image forming apparatus cannot send an end notification to the finisher apparatus. As a result, the finisher controller for turning off the finisher apparatus in response to the reception of the end notification cannot receive the notification because the supply of power to the printer unit is stopped, so that the finisher controller cannot turn off the finisher apparatus.
Even in a case where the supply of power not only to the above printer but also to pathway devices between the main body controller and the finisher controller is stopped, the image forming apparatus cannot send the end notification to a post-processing apparatus. As a result, the finisher apparatus cannot execute the shutdown function, so that the finisher apparatus cannot be turned off.